1. Field of the Invention
The present invention relates to dry bakery product, a process for preparing them and a novel bakery ingredient employed in that preparation. more particularly the invention is concerned with crackers and a process for their preparation.
2. Description of Related Art
Conventionally, so-called premium crackers (also known as cream crackers or fermented crackers) are generally manufactured by preparing a mixture of flour, water, yeast and sugar, followed by a conventional sponge fermentation involving low speed mixing of dough ingredients (flour, water, yeast and often salt) on a dough mixer for 20-25 minutes or using a combination of low and high speed mixing. The mixture is fermented in bulk for the time stated in the recipe, commonly 18-24 hours (sponge fermentation). During this fermentation the yeast ferments out the sugars while the lactic acid bacteria that are always present in commercial yeast products assimilate some of the products of yeast and lactic acid bacteria. The mixture provides components that contribute to taste, texture and appeal of premium crackers. Such a mixture is then added to the rest of the ingredients which make up the premium cracker dough and processing proceeds in a conventional way.
On a laboratory scale two main conventional ways of processing can be distinguished: classical premium cracker manufacture and starter culture based premium cracker manufacture, see R. C. Hoseney and various collaborators in Cereal Chemistry, 57(3) 185-8 1980, 57(4) 249-52 1980, 62(3) 158-62 1985, 66(1) 7-10 1989. Both involve the preparation of a pre-fermentation slurry from flour and water, fermented with a lactobacilli containing yeast or with yeast and a separately added lactobacilli starter culture. This prefermented slurry is then added to the sponge fermentation mixture and the sponge fermentation step is performed which typically takes 18 hours at 30xc2x0 C. In practice, these prefermentation steps are not carried out but a sponge fermentation is done as the first step. It is followed by the dough fermentation step which takes typically 4 hours at 30xc2x0 C. Dough handling is completed in the usual way by rolling, laminating and cutting. Total production time before baking is generally well over 20 hours. This is schematically set out in FIG. 1.
The process can be shortened by using the continuous or semi-continuous pre-culture process involving a yeast based fermentation and a lactic acid based fermentation. Quantities of these fermentation broths are then added to the final dough mixture as required. This process is used in industry and is schematically set out in FIG. 2. A problem likely to occur with this approach is the difficulty of maintaining adequate process control so as to ensure a consistent addition of the fermented ingredients to the main dough ingredients. An incorrectly matured fermented ingredient will produce a substandard final product. The pre-fermentation procedures can reduce the manufacturing time per batch to a few hours. However, the pre-fermentation processes require continuous maintenance. The fermentations periodically require to be re-set with resulting considerable production inconvenience. Additionally, the total number of processing steps is not greatly reduced. In EP-B-0 153 057 a process is described in which flour is continuously fermented in a 10% aqueous slurry with lactobacilli and optionally yeast. This slurry is then added to the cracker dough. The total process is described by D. Fox et al in Australian Journal of Biotechnology, 3(2) 139-43 1989. This process in practice requires the fermented flour slurry to be produced on the same location where the cracker dough is produced. Also, the continuous fermentation is difficult to adapt to required variations in production volume of the crackers
Thus, all methods as described above have various disadvantages, mainly being long process times (fermentation and proofing) and a large number of process steps which makes processing complicated and involves extensive and complicated equipment. For example, a cracker manufacturer who wishes to operate the process using the prefermentation method instead of the more classical methods will need to invest in new, different and complicated equipment.
Hence, there is an need for an improved process for manufacturing dry bakery products such as rusk, crackers (including fermented and cream crackers, chemically leavened crackers, soda crackers, etc), dry biscuits and the like. Such process should involve fewer process steps, and/or lead to shorter and simplified processing and/or less investment in expensive machinery on the part of the cracker manufacturer. The process may also lead to dry baked goods with improved properties such as flavour, taste, texture or appearance.
It has now been found that dry baked goods can be produced, with a simple process for preparing the dough, which does not involve the use of diluted aqueous slurries of fermented flour and/or sponges by the manufacturer, by using a new bakery ingredient as hereinafter described.
The new bakery ingredient comprises fermented cereal germs, prepared by subjecting cereal germs to fermentation with lactic acid bacteria and optionally yeast. The fermentation may be carried out in solid state or in an aqueous medium. If carried out in an aqueous medium, the fermented cereal germs according to the invention are generally obtained as a wet slurry. This slurry can be used as such as a baking improver, but it may advantageously be concentrated by partial removal of water. Furthermore, by substantially complete removal of water it may be converted into a dry form, which has the additional benefit of improved storage stability and easy handling and shipping. Additionally, it is also possible to use liquid extracts of the fermented cereal germs which may in turn be converted to concentrated or a dry form. The bakery ingredient comprising the fermented cereal germs in any of the forms described above constitutes one aspect of the invention.
The cereal germs may be derived from wheat, barley, rye, corn, rice and other edible cereals. Germs from wheat or barley are preferred, particularly wheat.
The fermentation for obtaining the fermented cereal germs is carried out using standard fermentation techniques, preferably using starter cultures comprising lactic acid producing bacteria. More preferred lactic acid bacteria are lactobacilli such as Lactobacillus plantarum or Lactobacillus brevis. Yeast may be added to the starter cultures used, in particular Saccharomyces cerevisiae. 
The fermentation of the cereal germs can be carried out using a level of solids of between 5 and 95% by weight, preferably between 5 and 40%, more preferably between 20-40%, and can be carried out in any hygienic fermentation vessel with provisions for good mixing and temperature control. The temperature is generally kept at 15-50xc2x0 C., preferably 25-40xc2x0 C. Prior to fermentation the fermentation mixture may be pasteurized or sterilized e.g. by using HTST equipment, whereafter the lactic acid producing bacteria and optionally the yeast are added to the mixture. The fermentation process is carried out for 15 minutes to 72 hours, preferably 8-72 hours, more preferably 30-72 hours, most preferably 48-72 hours, and the matrix may be pasteurized or sterilised again in order to inactivate viable organisms and/or enzymes.
Before or during the fermentation the cereal germs may be treated with various enzymes, preferably those having protease and/or carbohydrase (particularly amylase, amylo-glucosidase, hemi-cellulase or cellulase) activity. Such treatment is preferably carried out simultaneously with the fermentation. The treatment leads to improved properties of the fermented cereal germs which in turn leads to improved processing of the dough as well as flavour/taste and odour of the cracker in which the bakery ingredient is used.
In addition to the cereal germs, the starter culture, and optionally the yeast and/or the enzymes, the fermentation mixtures may also include cereal (particularly wheat) flour and other ingredients such as salt, malt, sugars such as dextrose, sucrose or molasses, and proteins (particularly gluten) which may be (partly) chemically or enzymatically degraded.
The resulting fermentation broth can be processed in various ways, including stabilising/preserving the final product. Such processing may include chilling (e.g. to refrigerator temperatures), concentration by evaporation of water leading to a concentrated slurry or paste, or processing leading to a solid product such as deep freezing or drying (e.g. by use of spray-dryer, freeze dryer, ring-dryer, fluid-bed dryer or vacuum-band dryer equipment). If before such further processing solids are removed from the fermentation broth an extract is obtained which can be further processed as described above. Before or after drying the fermentation product may be combined with carrier materials (e.g. modified starch or maltodextrin) or with other dry ingredients commonly used for bakery applications, such as dry yeast, dry flour or dry sugars. The resulting mixture can be subjected to further drying if desired. The final dry product should preferably have a moisture content of 10% or less, more preferably below 6%. During or after fermentation of the cereal germs other parts of cereals (e.g. bran or endosperm) may also be added.
The bakery ingredient according to the invention may be used as a baking improver in the preparation of dry bakery products, particularly crackers. The term xe2x80x9cbaking improverxe2x80x9d is herein to be understood to be a composition comprising at least one component which facilitates or improves the processing of dough or improves the properties of dough and/or of the bakery products prepared therefrom. Such improvements may be in: processing time, fermentation time, proofing time, dough rheology, dough handling, specific volume, dough stability, dough flexibility, dough tolerance, appearance of the bakery products prepared from the dough (e.g. colour), organoleptic properties of the bakery products (flavour, taste, odour), structure or texture of the bakery products, staling properties, shelf life, etc. The bakery ingredient according to the invention may be added as such to flour or dough or may be first combined with other bakery ingredients, including bakery ingredients which are known in the art as baking improvers according to the definition above, such as enzymes (xcex1-amylase, xylanase, glucose oxidase, peroxidase, etc.), emulsifiers (mono- and diglycerides), salts (e.g. NaCl and NaHCO3), chemical oxidizers (e.g. ascorbic acid and KBrO3) and proteins (particularly gluten) which may be (partly) chemically or enzymatically degraded.
Thus, a further aspect of the invention is a new process for the preparation of premium crackers in which the bakery ingredient according to the invention is incorporated in the dough prior to baking, whereafter the dough is further processed and baked as known in the art. The dough comprising the bakery ingredient according to the invention is another aspect of the invention. The preparation of the dough according to the invention can be carried out as a one-step process, in which all ingredients, including the bakery ingredient according to the invention, are mixed at the same time and the resulting dough processed in the usual way.